Touchscreen

ABSTRACT

A touchscreen includes a plurality of X electrodes extending in a first direction and arranged in parallel in a second direction, a plurality of Y electrodes extending in the second direction so as to intersect the X electrodes and arranged in parallel in the first direction, and pedestal layers formed at respective intersections between the plurality of X electrodes and the plurality of Y electrodes, wherein an intersection portion of each Y electrode is formed under the pedestal layer, wherein a part of an intersection portion of each X electrode is formed on the pedestal layer and both ends thereof are electrically connected to adjacent electrode portions of the X electrodes, and wherein a profile of a portion of the pedestal layer intersecting the intersection portion of the X electrode has a nonlinear shape when viewed from a direction perpendicular to the substrate.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority from Japanese application JP2011-241848 filed on Nov. 4, 2011 the content of which is herebyincorporated by reference into this application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a touchscreen, and particularly to atouchscreen capable of reducing that a pattern of an electrodeintersection portion is seen.

2. Description of the Related Art

As main types of a touchscreen, a type of detecting variations in lightand a type of detecting variations in electrical characteristics areknown. In addition, as the type of detecting variations in electricalcharacteristics, a capacitance coupling type is known.

As a capacitance coupling type touchscreen in the related art, asdisclosed in JP 2009-265748A or the like, a touchscreen which has aplurality of X electrodes and a plurality of Y electrodes intersectingthe X electrodes is known.

In the above-described touchscreen disclosed in JP 2009-265748A or thelike, the Y electrodes are formed in an electrode pattern where anintersection portion and an electrode portion wider than theintersection portion are alternately disposed in a plurality, and the Xelectrodes are formed in an electrode pattern where an intersectionportion and an electrode portion wider than the intersection portion arealternately disposed in a plurality.

In addition, the intersection portion of the Y electrode, the electrodeportion of the Y electrode, and the electrode portion of the X electrodeare formed on a substrate. Further, an intersection portion of the Xelectrode is formed on an insulating interlayer formed on the substrate,and both ends of the intersection portion of the X electrode arerespectively electrically connected to the adjacent electrode portionsof the X electrodes via a contact hole formed in the insulatinginterlayer. Furthermore, the X electrode and the Y electrode are made ofa material with high transmittance, for example, a transparentconductive material such as ITO (Indium Tin Oxide).

However, in the capacitance coupling type touchscreen in the relatedart, when viewed from a specific direction, the contact hole portion isrecognized by a user due to reflection at the contact hole portion, andthereby there is a problem in that visual quality deteriorates.

SUMMARY OF THE INVENTION

The present invention has been made in order to solve theabove-described problem, and an object of the present invention is toprovide a technique capable of reducing that a pattern of an electrodeintersection portion is recognized by a user due to reflection in atouchscreen.

The above-described and other objects and novel features of the presentinvention will become apparent through the description of the presentspecification and the accompanying drawings.

An outline of the invention disclosed in the present specification isdescribed representatively and briefly as follows.

(1) A touchscreen including a substrate; a plurality of X electrodesthat extend on the substrate in a first direction and are arranged inparallel in a second direction intersecting the first direction; aplurality of Y electrodes that extend on the substrate in the seconddirection so as to intersect the X electrodes and are arranged inparallel in the first direction; and pedestal layers that are formed atrespective intersections between the plurality of X electrodes and theplurality of Y electrodes, wherein each of the Y electrodes includes anintersection portion intersecting the X electrode and an electrodeportion formed in the same layer as the X electrode so as to beseparated from the X electrode, wherein each of the X electrodesincludes an intersection portion intersecting the Y electrode and anelectrode portion formed in the same layer as the Y electrode so as tobe separated from the Y electrode, wherein the intersection portion ofeach Y electrode is formed under the pedestal layer, wherein a part ofthe intersection portion of each X electrode is formed on the pedestallayer and both ends thereof are electrically connected to adjacentelectrode portions of the X electrodes, and wherein a profile of aportion of the pedestal layer intersecting the intersection portion ofthe X electrode has a nonlinear shape when viewed from a directionperpendicular to the substrate.

(2) The touchscreen in (1), wherein a profile of the pedestal layer is apolygonal shape of which the number of sides is equal to or more than apentagonal shape when viewed from a direction perpendicular to thesubstrate.

(3) The touchscreen in (1), wherein a profile of the pedestal layer is acircular shape when viewed from a direction perpendicular to thesubstrate.

(4) The touchscreen in (2) or (3), wherein both ends of the electrodeportion of the Y electrode in the first direction and both ends of theelectrode portion of the X electrode in the second direction are formedunder the pedestal layer.

(5) The touchscreen in (1), wherein the pedestal layer has an ellipticalshape of which a long axis direction is an extending direction of theintersection portion of the X electrode when viewed from a directionperpendicular to the substrate.

(6) The touchscreen in (5), wherein both ends of each of the electrodeportions of the plurality of X electrodes in the second direction areformed under the pedestal layer.

(7) The touchscreen in any one of (1) to (6), wherein the pedestal layeris formed in a tapered shape of which a thickness of a side surfacegradually increases toward a planarized portion on an opposite side to asurface coming into contact with the substrate.

(8) The touchscreen in any one of (1) to (7), further including an indexmatching layer that is formed on the substrate, wherein the Xelectrodes, the Y electrodes, and the pedestal layers are formed on theindex matching layer.

(9) The touchscreen in any one (1) or (8), wherein the electrode portionof the X electrode and the electrode portion of the Y electrode have arhombic shape when viewed from the direction perpendicular to thesubstrate.

(10) The touch panel in anyone of (1) to (9), further including aprotective layer that is formed so as to cover the X electrodes and theY electrodes.

Description of effects which can be achieved by the representativeinvention disclosed in the present specification is as follows.

According to the touchscreen of the present invention, it is possible toreduce that a pattern of an electrode intersection portion is recognizedby a user due to reflection.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a plan view of an electrode intersection portion of atouchscreen according to an embodiment of the present invention.

FIG. 1B is a cross-sectional view illustrating a cross-sectionalstructure taken along the line 1B-1B′ of FIG. 1A.

FIG. 2 is a diagram illustrating a modified example of the touchscreenaccording to the embodiment of the present invention.

FIG. 3A is a plan view of the electrode intersection portionillustrating effects of the touchscreen according to the embodiment ofthe present invention.

FIG. 3B is a cross-sectional view illustrating a cross-sectionalstructure taken along the line 3B-3B′ of FIG. 3A.

FIG. 4 is a plan view illustrating an electrode pattern of a touchscreenof a display device with the touchscreen in the related art.

FIG. 5 is a cross-sectional view illustrating a cross-sectionalstructure taken along the line V-V′ shown in FIG. 4.

FIG. 6 is a cross-sectional view illustrating a cross-sectionalstructure taken along the line VI-VI′ shown in FIG. 4.

FIG. 7 is a side view illustrating a schematic configuration of adisplay device with a touchscreen.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments of the present invention will be described indetail with reference to the accompanying drawings.

In addition, constituent elements with the same function are given thesame reference numeral throughout the drawings for describing theembodiments, and repeated description thereof will be omitted. Further,the following embodiment is not intended to construe the claims of thepresent invention in a limited sense.

Schematic configuration of display device with touchscreen

FIG. 7 is a side view illustrating a schematic configuration of adisplay device with a touchscreen. In addition, FIG. 7 shows a casewhere the display panel is a liquid crystal display panel 30.

The display device with a touchscreen shown in FIG. 7 includes theliquid crystal display panel 30, a capacitance coupling type touchscreen20 disposed on a surface on an observer side of the liquid crystaldisplay panel 30, and a backlight 40 disposed under a surface on anopposite side to the observer side of the liquid crystal display panel30.

As the liquid crystal display panel 30, a liquid crystal display panelof, for example, an IPS type, a TN type, a VA type, or the like, isused.

The touchscreen 20 includes a plurality of X electrodes which extend ina first direction and are arranged in parallel with a predeterminedarrangement pitch in a second direction intersecting the firstdirection, and a plurality of Y electrodes which extend in the seconddirection so as to intersect the X electrodes and are arranged in thefirst direction with a predetermined arrangement pitch.

Further, FIG. 7 schematically shows a case where capacitors C1 and C3are formed between the finger 50 of an observer and the X electrodes,and a capacitor C2 is formed between the finger 50 of the observer andthe Y electrode. The touchscreen 20 shown in FIG. 7 detects acapacitance difference between coupling capacitances of the X electrodeand the Y electrode, and detects touched position coordinates in a touchplane of the touchscreen 20, which are touched by the finger 50 of theobserver.

Touchscreen in the Related Art

FIGS. 4 to 6 are diagrams illustrating a capacitance coupling typetouchscreen in the related art, wherein FIG. 4 is a plan viewillustrating an electrode pattern of the capacitance coupling typetouchscreen in the related art; FIG. 5 is a cross-sectional viewillustrating a cross-sectional structure taken along the line V-V′ shownin FIG. 4; and FIG. 6 is a cross-sectional view illustrating across-sectional structure taken along the line VI-VI′ shown in FIG. 4.

The capacitance coupling type touchscreen in the related art includes aplurality of X electrodes which extend in a first direction (forexample, the X direction) and are arranged in parallel with apredetermined arrangement pitch in a second direction (for example, theY direction) intersecting the first direction, and a plurality of Yelectrodes which extend in the second direction so as to intersect the Xelectrodes and are arranged in the first direction with a predeterminedarrangement pitch.

The plurality of Y electrodes are formed in an electrode pattern wherean intersection portion 2 a and an electrode portion 2 b wider than theintersection portion 2 a are alternately disposed in a plurality in thesecond direction. The plurality of Y electrodes are disposed on asurface of a substrate 11 on the observer side and are covered by aninsulating layer 12 which is formed thereon. As the substrate 11, atransparent insulating substrate such as, for example, glass is used.

The plurality of X electrodes are formed in an electrode pattern wherean intersection portion 1 a and an electrode portion 1 b wider than theintersection portion 1 a are alternately disposed in a plurality in thefirst direction. The intersection portion 1 a of each of the pluralityof X electrodes is formed in a layer different from the Y electrode andplanarly intersects the intersection portion 2 a of each of the Yelectrodes. The electrode portion 1 b of the plurality of X electrodesis formed in the same layer as the electrode portion 2 b of each of theY electrodes so as to be separated from the Y electrodes. Here, theelectrode portion 1 b of the X electrode and the electrode portion 2 bof the Y electrode have a rhombic shape when viewed from the directionperpendicular to the substrate 11.

The electrode portion 1 b of each of the plurality of X electrodes iscovered by the insulating layer 12 in the same manner as the Yelectrode. The intersection portion 1 a of each of the plurality of Xelectrodes is disposed on the insulating layer 12 and is covered by aprotective layer 13 which is formed thereon.

The intersection portion 1 a of the X electrode planarly intersects theintersection portion 2 a of the Y electrode, and is electrically andmechanically connected to two adjacent electrode portions 1 b with theintersection portion 2 a interposed therebetween via contact holes 12 aformed in the insulating layer 12 which is an insulating interlayerbetween the intersection portion 1 a of the X electrode and the Yelectrode.

In plan view, the electrode portion 2 b of the Y electrode is disposedbetween the two adjacent intersection portions 1 a of the X electrode,and the electrode portion 1 b of the X electrode is disposed between thetwo adjacent intersection portions 2 a of the Y electrode.

In addition, the X electrode and the Y electrode are made of a materialhaving high transmittance, for example, a transparent conductivematerial such as ITO (Indium Tin Oxide).

However, in the capacitance coupling type touchscreen in the relatedart, there is a problem in that, when the touchscreen is viewed from aspecific direction, the contact hole portion is recognized by a user dueto reflection at the contact hole portion, and thus visual qualitydeteriorates.

Embodiment

FIGS. 1A and 1B are diagrams illustrating a touchscreen according to anembodiment of the present invention, wherein FIG. 1A is a plan view ofan electrode intersection portion, and FIG. 1B is a cross-sectional viewillustrating a cross-sectional structure taken along the line 1B-1B′ ofFIG. 1A.

In the present embodiment as well, as shown in FIG. 4, the touchscreenincludes a plurality of X electrodes which extend in a first direction(for example, the X direction) and are arranged in parallel with apredetermined arrangement pitch in a second direction (for example, theY direction) intersecting the first direction, and a plurality of Yelectrodes which extend in the second direction so as to intersect the Xelectrodes and are arranged in the first direction with a predeterminedarrangement pitch.

The plurality of Y electrodes are formed in an electrode pattern wherean intersection portion 2 a and an electrode portion 2 b wider than theintersection portion 2 a are alternately disposed in a plurality in thesecond direction. The plurality of Y electrodes are disposed on asurface of a substrate 11 on the observer side and are covered by aprotective layer 13 which is formed thereon. As the substrate 11, atransparent insulating substrate such as, for example, glass is used.

The plurality of X electrodes are formed in an electrode pattern wherean intersection portion 1 a and an electrode portion 1 b wider than theintersection portion 1 a are alternately disposed in a plurality in thefirst direction. The intersection portion 1 a of each of the pluralityof X electrodes is formed so as to stride over a pedestal layer 15 andplanarly intersects the intersection portion 2 a of each of the Yelectrodes. The electrode portion 1 b of each of the plurality of Xelectrodes is formed in the same layer as the electrode portion 2 b ofeach of the Y electrodes so as to be separated from the Y electrodes.

The plurality of X electrodes are covered by the protective layer 13which is formed thereon. In addition, the electrode portion 1 b of the Xelectrode and the electrode portion 2 b of the Y electrode have arhombic shape when viewed from the direction perpendicular to thesubstrate 11.

In the present embodiment, the pedestal layer 15 is formed at a partwhere the intersection portion 1 a of the X electrode intersects theintersection portion 2 a of the Y electrode. The pedestal layer 15 has aprofile of an elliptical shape in plan view.

As described above, the intersection portion 1 a of the X electrode isformed so as to stride over the pedestal layer 15. Thereby, theintersection portion 1 a of the X electrode planarly intersects theintersection portion 2 a of the Y electrode, and is electrically andmechanically connected to two adjacent electrode portions 1 b of the Xelectrode with the intersection portion 2 a interposed therebetween.

In plan view, the electrode portion 2 b of the Y electrode is disposedbetween the two adjacent intersection portions 1 a of the X electrode,and the electrode portion 1 b of the X electrode is disposed between thetwo adjacent intersection portions 2 a of the Y electrode. In addition,the X electrode and the Y electrode are made of a material having hightransmittance, for example, a transparent conductive material such asITO (Indium Tin Oxide).

As described above, the present embodiment is characterized in that thepedestal layer 15 is provided at the part where the intersection portion1 a of the X electrode intersects the intersection portion 2 a of the Yelectrode in order to omit the contact hole 12 a formed in theinsulating layer 12 in the touchscreen in the related art.

Here, the pedestal layer 15 is formed in a tapered shape where thethickness of the side surface 15 b gradually increases toward theplanarized portion 15 a on an opposite side to the surface coming intocontact with the substrate 11.

In the present embodiment, the contact hole 12 a formed in theinsulating layer 12 is omitted from the touch panel in the related artby providing the pedestal layer 15 at the portion where the intersectionportion 1 a of the X electrode intersects the intersection portion 2 aof the Y electrode. Therefore, it is possible to solve the problem that,when viewed from a specific direction, the contact hole portion isrecognized by a user due to reflection at the contact hole portion andthereby visual quality deteriorates.

However, at the side surface 15 b with a tapered shape of theintersection portion 1 a of the X electrode formed so as to cover thepedestal layer 15, reflectance is increased than the surroundings andreflection becomes obvious, including optical interference, andparticularly, it is expected that visual quality in the reflectiondeteriorates.

As shown in FIG. 1B, it is possible to reduce the interference by addingan index matching layer 16; however, visual quality deterioration at theside surface 15 b with a tapered shape due to reflection cannot bereduced.

The deterioration in the visual quality due to reflection is caused bythe side surface 15 b with a tapered shape, and is caused by reflectedlight at each side surface 15 b having directionality in a directionperpendicular to each side surface 15 b, in a case where a profile ofthe pedestal layer 15 is a rectangular shape, as shown in FIG. 3B.

Therefore, in the present embodiment, a profile of the pedestal layer 15when viewed from the direction perpendicular to the substrate 11 ischaracterized in an elliptical shape of which the long axis direction isan extending direction of the intersection portion 1 a of the Xelectrode. Thereby, the side surface 15 b with a tapered shape becomes anonlinear shape which is a convex shape with respect to the reflectiondirection so as to diffuse reflected light at the side surface 15 b anddecrease a difference between luminance due to the reflected light atthe side surface 15 b and surrounding luminance, and thereby it ispossible to reduce that the pattern of the electrode intersectionportion is seen.

Here, preferably, the smaller the area of the pedestal layer 15 is, thefurther achieved the improvement effect is; however, the area cannot betoo small due to a restriction of a resistance value of the X electrode.

Further, in the present embodiment, for the above-described reasons,when viewed from the direction perpendicular to the substrate 11, it isclear that a shape of the part intersecting the intersection portion 1 aof the X electrode in the pedestal layer 15 is preferably a nonlinearshape.

Further, a profile of the pedestal layer 15 when viewed from thedirection perpendicular to the substrate 11 is not limited to anelliptical shape, and may be an obtuse polygonal shape, or may be acircular shape as shown in FIG. 2. In addition, FIG. 2 is a diagramillustrating a modified example of the pedestal layer 15 according tothe present embodiment and is a plan view of the electrode intersectionportion.

Further, although the intersection portion 2 a of the Y electrode isformed under the pedestal layer 15, and the intersection portion 1 a ofthe X electrode is formed on the pedestal layer 15 in FIG. 1B, theintersection portion 1 a of the X electrode may be formed under thepedestal layer 15, and the intersection portion 2 a of the Y electrodemay be formed on the pedestal layer 15 as shown in FIG. 3B. Aconfiguration in this case is shown in FIGS. 3A and 3B.

However, as shown in FIGS. 3A and 3B, since it is necessary for bothends of the electrode portion 1 b of the X electrode in the extendingdirection of the X electrode to be formed so as to cover a part of theplanarized portion 15 a and the side surface 15 b of the pedestal layer15 in terms of manufacturing processes, a reflection region is furtherincreased than that of the configuration shown in FIGS. 1A and 1B, whichthus is not preferable. In addition, FIGS. 3A and 3B are diagrams fordescribing effects of the touchscreen according to the presentembodiment.

In addition, although, in the above-described embodiment, the displaydevice with a touchscreen where the touchscreen is provided on theliquid crystal display panel which is an example of the display panel,the present invention is not limited thereto, and may be applied to adisplay device with a touchscreen where the touchscreen is provided onother display panels such as an organic EL display panel or an inorganicEL display panel.

As above, although the invention made by the present inventor has beendescribed in detail based on the embodiment, the present invention isnot limited to the embodiment and may be variously modified withoutdeparting from the spirit thereof.

In other words, while there have been described what are at presentconsidered to be certain embodiments of the invention, it will beunderstood that various modifications may be made thereto, and it isintended that the appended claims cover all such modifications as fallwithin the true spirit and scope of the invention.

What is claimed is:
 1. A touchscreen comprising: a substrate; aplurality of X electrodes that extend on the substrate in a firstdirection and are arranged in parallel in a second directionintersecting the first direction; a plurality of Y electrodes thatextend on the substrate in the second direction so as to intersect the Xelectrodes and are arranged in parallel in the first direction; andpedestal layers that are formed at respective intersections between theplurality of X electrodes and the plurality of Y electrodes, whereineach of the Y electrodes includes an intersection portion intersectingthe X electrode and an electrode portion formed in the same layer as theX electrode so as to be separated from the X electrode, wherein each ofthe X electrodes includes an intersection portion intersecting the Yelectrode and an electrode portion formed in the same layer as the Yelectrode so as to be separated from the Y electrode, wherein theintersection portion of each Y electrode is formed under the pedestallayer, wherein a part of the intersection portion of each X electrode isformed on the pedestal layer and both ends of the intersection portionof each X electrode are electrically connected to adjacent electrodeportions of the X electrodes, and wherein a profile of a portion of thepedestal layer intersecting the intersection portion of the X electrodehas a nonlinear shape when viewed from a direction perpendicular to thesubstrate.
 2. The touchscreen according to claim 1, wherein a profile ofthe pedestal layer is a polygonal shape of which the number of sides isequal to or more than a pentagonal shape when viewed from a directionperpendicular to the substrate.
 3. The touchscreen according to claim 1,wherein a profile of the pedestal layer is a circular shape when viewedfrom a direction perpendicular to the substrate.
 4. The touchscreenaccording to claim 2 or 3, wherein both ends of the electrode portion ofthe Y electrode in the first direction and both ends of the electrodeportion of the X electrode in the second direction are formed under thepedestal layer.
 5. The touchscreen according to claim 1, wherein thepedestal layer has an elliptical shape of which a long axis direction isan extending direction of the intersection portion of the X electrodewhen viewed from a direction perpendicular to the substrate.
 6. Thetouchscreen according to claim 5, wherein both ends of each of theelectrode portions of the plurality of X electrodes in the seconddirection are formed under the pedestal layer.
 7. The touchscreenaccording to claim 6, wherein the pedestal layer is formed in a taperedshape of which a thickness of a side surface gradually increases towarda planarized portion on an opposite side to a surface coming intocontact with the substrate.
 8. The touchscreen according to claim 7,further comprising: an index matching layer that is formed on thesubstrate, wherein the X electrodes, the Y electrodes, and the pedestallayers are formed on the index matching layer.
 9. The touchscreenaccording to claim 8, wherein the electrode portion of the X electrodeand the electrode portion of the Y electrode have a rhombic shape whenviewed from the direction perpendicular to the substrate.
 10. The touchpanel according to claim 9, further comprising: a protective layer thatis formed so as to cover the X electrodes and the Y electrodes.